1. Field of Invention
The present invention relates to a securing structure, and method for securing, an energy absorber which is disposed on a compartment side of a structural member of a vehicle body, such as a pillar, a roof side rail, a header and the like, and which is covered with an interior trim material, such as a pillar garnish, a roof lining and the like. The energy absorber absorbs an impact energy transmitted thereto via the interior trim material.
2. Description of Related Art
In motor vehicles, particularly, in passenger cars, an energy absorber is disposed in a space between an interior trim member and a structural member of a vehicle body. Therefore, if an impact load is applied in a direction from the interior trim member to the structural member, the energy absorber deforms to absorb energy of the impact load. Normally employed energy absorbers are, for example, a grid rib member, a urethane pad, a steel member formed by bending a thin steel sheet so as to have a hat-like sectional shape, and the like. Also employed as an energy absorber is a generally-termed hybrid pipe (as described in U.S. Pat. No. 5, 680, 886) that is formed of a metal foil core member and sheets of a material other than metal that are laid on opposite side surfaces of the core member. In the hybrid pipe, the core member and the sheets on the opposite side surfaces of the core member are corrugated so that ridges and grooves alternate in a direction of an axis of the pipe.
A hybrid pipe, after being formed, can easily be changed into a desired sectional shape by correspondingly shaping the pipe. Furthermore, the energy absorption characteristic of a hybrid pipe can be adjusted by changing a dimension of the hybrid pipe measured between an outermost point in the curved outer surface of a ridge or protruded portion and an innermost point in the curved inner surface of a groove or recessed portion, that is, the generally-termed apparent plate thickness of the hybrid pipe, or changing the pitch between adjacent protruded portions (recessed portions), and the like. Thus, a hollow-shaped energy absorber represented by a hybrid pipe or the like has properties desirable for an energy absorber.
Vehicle body structural members to be installed at certain locations in a vehicle body are formed into three-dimensionally bent shapes in order to meet strength requirements and design needs. To conform to the three-dimensionally bent shape of a structural member, a substantially straight-formed energy absorber is subjected to a bending process. Normally, the energy absorber bending process is time-consuming and disadvantageous in cost. Therefore, in some cases, a plurality of energy absorbers of the same sectional shape or dimensions are screwed, at opposite ends of each absorber, to a structural member, so that the energy absorbers function as a single unit.
In some other cases, the interval between a structural member and an interior trim material disposed at a compartment-side of the structural member, which interval is necessary to absorb a predetermined amount of energy, varies in the direction of a length of the structural member. In such a case, a plurality of energy absorbers of different sectional shapes or dimensions are screwed at opposite ends of each absorber to the structural member, so that the energy absorbers function as a single unit.
The aforementioned operation of securing a plurality of energy absorbers individually to a structural member is time and labor-consuming.